St. Louis City hall was evacuated early Tuesday morning after a suspicious container was found.

A bomb tech examined a bag outside St. Louis City Hall Tuesday

A bomb tech examined a bag outside St. Louis City Hall Tuesday

ST. LOUIS, Mo. (KMOV.com) -- St. Louis City Hall was evacuated early Tuesday morning after two cylinders and a bag were found at three separate entrances.

According to city spokeswomen Maggie Crane, two carbon dioxide cylinders and a bag were found at three separate entrances around 7:30 a.m. The suspicious materials were located in the front, back and north side of City Hall.

Crane posted on her Twitter page that "no specific threat or reason" was found.

St. Louis Police Chief Sam Dotson said bomb and arson conducted a “disruption” of the suspicious materials. He warned that people outside the building would hear a “loud bang” during the detonations. Dotson said authorities conducted a search of other downtown buildings as a safety precaution but found no threats.

Officials with the ATF and FBI said they assisted the City of St. Louis. An ATF official told News 4 they had a K-9 and explosives team at the scene. Authorities said they are reviewing surveillance footage captured by the cameras located outside the building.

Fourteen Aldermen, including two new members, were scheduled to be sworn-in during a meeting inside City Hall Tuesday morning. St. Louis Board of Aldermen President Lewis Reed said the swearing-in ceremony will take place at a park outside the building.

The scene was cleared and all roadways around City Hall reopened at 12:30 p.m.